Hepatitis B vaccination among 1997-2011 birth cohorts in rural China: the potential for further catch-up vaccination and factors associated with infant coverage rates

Figures & data

Table 1. Institutional births and infant hepatitis B vaccination coverage according to time after birth.*

		Institutional births	1st dose within 24 hours	1st dose within 48 hours	3rd dose within first year
Birth year	N	Percentage (%)	Percentage (%)	Percentage (%)	Percentage (%)
1997–1999	1168	64.5 (61.6, 67.2)	50.4 (47.5, 53.3)	54.6 (51.7, 57.5)	45.5 (42.6, 48.4)
2000–2002	1119	68.6 (65.8, 71.3)	59.6 (56.7, 62.5)	63.3 (60.4, 66.1)	57.5 (54.5, 60.4)
2003–2005	1240	72.2 (69.6, 74.7)	71.4 (68.8, 73.9)	75.1 (72.6, 77.5)	67.7 (65.1, 70.3)
2006–2007	1004	77.2 (74.5, 79.8)	76.6 (73.8, 79.2)	80.9 (78.3, 83.3)	73.1 (70.2, 75.8)
2008–2009	1065	81.4 (78.9, 83.7)	81.3 (78.8, 83.6)	85.6 (83.4, 87.7)	76.2 (73.6, 78.8)
2010–2011	702	81.6 (78.6, 84.4)	84.0 (81.1, 86.7)	89.2 (86.6, 91.4)	-

*Percentages according to birth year groups with 95% confidence intervals (in parentheses). Confidence intervals were calculated using the binomial distribution (exact).

Table 2. Variable definitions and descriptive statistics for regression variables (N = 5,625).

Variables	Definitions	Mean^a	SD^b
Institutional birth	Child born at township, county, or a higher-level hospital	.732
Birth year 1997	Born in 1997	.053
Birth year 1998	Born in 1998	.067
Birth year 1999	Born in 1999	.064
Birth year 2000	Born in 2000	.064
Birth year 2001	Born in 2001	.055
Birth year 2002	Born in 2002	.061
Birth year 2003	Born in 2003	.059
Birth year 2004	Born in 2004	.064
Birth year 2005	Born in 2005	.073
Birth year 2006	Born in 2006	.081
Birth year 2007	Born in 2007	.078
Birth year 2008	Born in 2008	.084
Birth year 2009	Born in 2009	.087
Birth year 2010	Born in 2010	.080
Birth year 2011	Born in 2011	.031
Male	Male	.525
Father’s education level	Education level, range 1-7^c	2.88	.84
Mother’s education level	Education level, range 1-7^c	2.64	.87
Migration	At least one parent is a migrant worker	.418
Income group 1	Income in 1st quintile^d	.231
Income group 2	Income in 2nd quintile^d	.219
Income group 3	Income in 3rd quintile^d	.161
Income group 4	Income in 4th quintile^d	.207
Income group 5	Income in 5th quintile^d	.182
True transmission route ind.	No. of identified true transmission routes; range, 0–5	2.09	1.76
False transmission route ind.	No. of identified false transmission routes; range, 0–2	.76	.77
Perceived protection 1	Vaccine is unknown or protection lasts <1 year	.379
Perceived protection 2	Protection lasts between 1 and 5 years	.369
Perceived protection 3	Protection lasts between 5 and 10 years	.106
Perceived protection 4	Protection lasts between 10 and 20 years	.048
Perceived protection 5	Protection lasts for more than 20 years	.099

^aDichotomous variables have a value of 1 when the responses corresponded to the statements in the definitions column and a value of 0 otherwise (e.g., if a boy was born at home, then Male = 1 and Institutional birth = 0). Hence, the mean values of dichotomous variables represent sample proportions.

^bSD is the standard deviation, for numerical variables.

^cEducation level, in increasing order: no schooling; primary school and below; junior middle school; senior middle school or technical school; junior college; undergraduate; postgraduate.

^dThe cut-off points were 2,750, 4,400, 6,667, and 10,000 Yuan per year.

Table 3. Logistic regression models for infant HBV vaccination status.

	Timely Birth Dose^a			Completed Vaccination^b
	Coef.	Std. err.	P	Coef.	Std. err.	P
Institutional birth	0.873	0.070	0.000	0.528	0.071	0.000
Birth year 1998	0.154	0.165	0.351	0.248	0.164	0.130
Birth year 1999	0.086	0.167	0.607	0.236	0.165	0.153
Birth year 2000	0.410	0.168	0.015	0.463	0.165	0.005
Birth year 2001	0.221	0.174	0.203	0.650	0.172	0.000
Birth year 2002	0.615	0.172	0.000	0.774	0.169	0.000
Birth year 2003	0.930	0.178	0.000	1.002	0.173	0.000
Birth year 2004	0.891	0.174	0.000	0.953	0.169	0.000
Birth year 2005	1.018	0.171	0.000	1.233	0.168	0.000
Birth year 2006	1.075	0.167	0.000	1.203	0.163	0.000
Birth year 2007	1.299	0.176	0.000	1.403	0.169	0.000
Birth year 2008	1.222	0.171	0.000	1.514	0.169	0.000
Birth year 2009	1.370	0.174	0.000	1.261	0.164	0.000
Birth year 2010	1.383	0.178	0.000
Birth year 2011	1.824	0.258	0.000
Male	0.017	0.063	0.790	−0.058	0.063	0.360
Father’s education level	0.008	0.045	0.859	−0.009	0.046	0.840
Mother’s education level	0.269	0.045	0.000	0.235	0.045	0.000
Migration	−0.052	0.065	0.418	−0.165	0.065	0.011
Income group 2	0.432	0.092	0.000	0.459	0.093	0.000
Income group 3	0.364	0.101	0.000	0.486	0.102	0.000
Income group 4	0.489	0.097	0.000	0.537	0.097	0.000
Income group 5	0.458	0.101	0.000	0.459	0.101	0.000
True transmission route index	0.166	0.022	0.000	0.148	0.022	0.000
False transmission route index	−0.043	0.050	0.388	−0.032	0.050	0.525
Perceived protection 2	0.279	0.074	0.000	0.354	0.074	0.000
Perceived protection 3	0.373	0.113	0.001	0.482	0.113	0.000
Perceived protection 4	0.674	0.169	0.000	0.739	0.167	0.000
Perceived protection 5	0.507	0.120	0.000	0.643	0.119	0.000
Constant	−2.128	0.186	0.000	−2.051	0.187	0.000

The dependent variables were dichotomous. Coefficients (coef.), standard errors (Std.err), and two-sided p-values are reported.

^aBasis outcome: had not received the first dose within 24 hours after birth (n = 5,625).

^bBasis outcome: had not received completed vaccination within the first year of life (n = 5,001).

Table 4. Vaccination status at the time of the survey.*

		Completed immunization	Partial immunization	Uncertain	No immunization
Birth year	N	Percentage (%)	Percentage (%)	Percentage (%)	Percentage (%)
1997–1999	1,273	74.9 (72.5, 77.3)	7.7 (6.3, 9.3)	9.5 (7.9, 11.3)	7.9 (6.4, 9.5)
2000–2002	1,154	82.6 (80.3, 84.7)	6.4 (5.1, 8.0)	6.3 (5.0, 7.9)	4.7 (3.5, 6.1)
2003–2005	1,272	88.3 (86.4, 90.0)	4.6 (3.5, 5.9)	4.9 (3.8, 6.2)	2.3 (1.5, 3.3)
2006–2007	1,027	91.0 (89.1, 92.7)	2.4 (1.6, 3.6)	5.0 (3.7, 6.5)	1.6 (0.9, 2.5)
2008–2009	1,085	91.2 (89.3, 92.8)	3.8 (2.7, 5.1)	3.9 (2.8, 5.2)	1.2 (0.6, 2.0)

*Percentages according to birth year groups with 95% confidence intervals (in parentheses). Confidence intervals were calculated using the binomial distribution (exact).